Even though Sophie's tone wasn't particularly harsh, Xiao Mu could sense that this wasn't a negotiation.
At the same time, Xiao Mu picked up on a crucial detail in Sophie's words. She said "Submission to the undead Lord," not "Submission to her."
"You're not the undead Lord?" Xiao Mu asked.
"Of course not. I'm just her subject. She's still on Eldoria," Sophie revealed, hinting that the undead Lord they would be submitting to was the same one currently being hunted by many Lords on Eldoria.
Xiao Mu and Xiao Hui weren't fools. They quickly pieced it together. The controversy surrounding the undead Lord hadn't died down, and the information shared by Lords in the World Chat was plentiful. They knew all about it.
So, the person before them wasn't the undead Lord. She didn't have that kind of aura anyway.